In 2015, Pope Francis plans to make climate change a personal issue for the world’s 1.2 billion Catholics. The Guardian’s John Vidal reports that Francis will publish an encyclical (a letter to the world's bishops), speak directly to United Nations leaders in the fall, and organize a summit of world religions—all aimed at pressuring countries to commit to a strong climate agreement at a Paris meeting next December. 

Catholics that have rallied for climate change action for years—most recently at recent climate talks in Lima, Peru—are thrilled with the Pope's efforts. “The anticipation around Pope Francis’s forthcoming encyclical is unprecedented," Neil Thorns, head of advocacy at Catholic development agency Cafod, told The Guardian. "We have seen thousands of our supporters commit to making sure their MPs know climate change is affecting the poorest communities.”

The only group Francis has offended are climate-change deniers—notably Cardinal George Pell, a former archbishop of Sydney who is in charge of the Vatican's budget. He argued in a 2011 speech that CO2 is "not a pollutant, but part of the stuff of life." Pell claimed, "Animals would not notice a doubling of CO2 and obviously plants would love it." Here in the U.S., Catholic climate-deniers like House Speaker John Boehner will have to reckon with Francis' call. Evangelical Christians have already warned that they will protest it. “The pope should back off,” Calvin Beisner, spokesman for the conservative Cornwall Alliance for the Stewardship of Creation, said. “The Catholic church is correct on the ethical principles but has been misled on the science. It follows that the policies the Vatican is promoting are incorrect. Our position reflects the views of millions of evangelical Christians in the U.S." 

Climate change isn’t a far-fetched cause for Christians, or anyone who cares about inequality. That's because, at its root, global warming comes from a relatively small number of countries and corporations, while poor populations suffer the most from its consequences. The point of an international treaty or accord is to get every country to act in everyone's best interest. “The monopolizing of lands, deforestation, the appropriation of water, inadequate agro-toxics are some of the evils that tear man from the land of his birth," Francis explained in October. "Climate change the loss of biodiversity and deforestation are already showing their devastating effects in the great cataclysms we witness."

People in the U.S. and Australia have the luxury to deny climate change exists. Most of Francis's flock do not.